#352 - Advanced 1D/2D Modeling with HEC-RAS (FY23)

Date: 4-8 April 2023

Objectives

This is an advanced course in applying computer program HEC-RAS. The course provides participants with the knowledge to effectively use computer program HEC-RAS to analyze difficult hydraulic conditions in natural and constructed channels, utilizing one-dimensional and two-dimensional modeling techniques.

Topics include: Developing terrain models for 2D modeling; developing Manning’s n layers; creating and modifying a 2D computational mesh; boundary conditions for 2D Flow Areas; hooking up 1D elements to 2D Flow Areas; running a combined 1D/2D model; viewing 1D/2D results with RAS Mapper; hydraulic structures inside of 2D areas; and detailed channel and floodplain modeling with 2D flow areas. Special topics for dam and levee breaching, and using 2D modeling for hydraulic structures, will also be included.

PDF material for the course Agenda, presentations, and workshops are provided below.

Instructors

Cameron Ackerman (Course Coordinator)
Stanford Gibson
Mark Jensen
Alex Kennedy
Alex Sanchez
Eric Tichanksy
Anton Rotter-Sieren
Steve Piper (RMA Contractor)

Terms of Use

Any use or reproduction of this material must be attributed to the US Army Corps of Engineers Hydrologic Engineering Center.

Agenda

Monday

Time		Topic	Objective	Material
0800-0900	L0	Introductions and pre-course activities	Welcome and discussion of class expectations	Agenda.pdf
0900-0945	L1.1	Example HEC-RAS Modeling	Overview of HEC-RAS capabilities using example applications for 2D modeling Introduction to the validation and verification of HEC-RAS. A demonstration of using HEC-RAS to create a 2D model will conclude the discussion.	1.1 Overview of HEC-RAS Modeling.pdf
1000-1015		Break
1015-1100	L1.2	Introduction to the 2D Equations	This presentation discusses the underlying 2D hydraulic equations used in HEC-RAS. Diffusion Wave and Full Shallow Water Equations in HEC-RAS will be discussed as well as scenarios where the equations are appropriate is also provided.	1.2 Introduction to 2D Equations.pdf
1100-1145	L1.3	Subgrid Bathymetry	Discussion on the use of sub-grid bathymetry for finite volume computations in HEC-RAS. The benefits of variable cell size on computational performance will be discussed.	1.3 HEC-RAS Subgrid Bathymetry.pdf
1145-1245		Lunch
1245-1345	L1.4	Creating an HEC-RAS Terrain	Developing a terrain model and creating dataset for 2D modeling. Introduction to terrain download capabilities.	1.4 Creating a RAS Terrain.pdf
1345-1445	W1.5	Creating an HEC-RAS Terrain Workshop	Hands- on work creating an HEC-RAS Terrain dataset	1.5 Workshop - Creating a RAS Terrain.pdf 1.5 W - Creating a RAS Terrain.zip
1445-1500		Break
1500-1545	L1.6	Mesh Generation and Refinement	This presentation will discuss the basic concepts of creating a 2D Mesh in HEC-RAS and then how to improve and refine a 2D Mesh with Breaklines and Refinement Regions. Examples of mesh quality will be reviewed.	1.6 Mesh Generation and Refinement.pdf
1545-1700	W1.7	Mesh Generation and Refinement Workshop	This workshop will provide hands-on experience in using HEC-RAS Mapper to create a 2D flow area mesh and refine it to capture high ground using breaklines and refinement regions	1.7 Workshop - Mesh Generation and Refinement.pdf 1.7 W - Mesh Generation.zip

Tuesday

Time		Topic	Objective	Material
0800-0845	L2.1	Boundary and Initial Conditions	The different types of boundary conditions and establishing initial conditions will be discussed.	2.1 Boundary and Initial Conditions.pdf
0845-0930	L2.2	Computational Parameters	Discussion of essential parameters and computational options for running a 2D model including equation choice, cell size considerations, and time step considerations.	2.2 Computational Parameters.pdf
0930-0945		Break
0945-1100	W2.3	Creating a Simple 2D Model Workshop	Students will create their first 2D model. Refinement of the model will be performed to understand the effect of model parameters.	2.3 Workshop - Creating a Simple 2D Model.pdf 2.3 W - Creating a Simple 2D Model.zip
1100-1130		Review
1130-1230		Lunch
1230-1315	L2.4	Visualization of HEC-RAS Results in HEC-RAS Mapper	An introduction to RAS Mapper is provided, specifically for visualizing HEC-RAS results.	2.4 RAS Mapper.pdf
1315-1345	D2.5	HEC-RAS Mapper Demonstration
1345-1400		Break
1400-1430	L2.6	Land Classification Data	This discussion will cover creating an Land Classification dataset for use with Manning's n values in RAS Mapper.	2.6 Land Classification Data.pdf
1430-1515	W2.7	Land Classification Data	Student will learn how to bring land cover data into a Land Classification dataset and associated Manning's n values.	2.7 Workshop - Mannings n Values.pdf 2.7 W - Land Cover ManningsN.zip
1515-1545		Review
		Kahoot!
1545-1630	L2.8	Advanced Computation Options	Discussion of more advanced parameters and computational options for running a 2D model including equation choices, turbulence, and matrix solvers.	2.8 Advanced Computation Options.pdf
1630-1700	L2.9	1D vs 2D Modeling	This presentation discusses 1D vs 2D modeling and how to choose the appropriate modeling method.	2.9 1D vs 2D Modeling.pdf

Wednesday

Time		Topic	Objective	Material
0800-0830	L3.1	Combined 1D/2D Modeling	Discussion of modeling channels with 1D rivers reaches/cross sections combined with floodplains/levees using 2D Flow Areas	3.1 Combined 1D2D Modeling.pdf
0830-0930	W3.2	Combined 1D/2D Modeling Workshop	Use a combined 1D/2D model to evaluate a protected area using 2D Flow Area and a Lateral Structure to define a levee. Levee over-topping and breaching will also be analyzed.	3.2 Workshop - Combined 1D2D Modeling.pdf 3.2 W - Combined 1D2D Modeling.zip
0930-1000		Review
1000-1015		Break
1015-1045	L3.3	Dam and Levee Breach Modeling with 2D Flow Areas	Discussion of how to use 2D Flow Areas with 1D reaches and storage areas to perform a dam breach analysis. Discussion on using the SA/2D Connection for modeling a dam, outlets, and the dam breach.	3.3 Dam Break Modeling 2D.pdf
1045-1115	L3.4	Determination of Dam Breach Parameters	This presentation will discuss estimating dam breach parameters for modeling dam breach scenarios.	3.4 Determination of Dam Breach Parameters.pdf
1115-1215		Lunch
1215-1345	W3.5	Dam Breach with 2D Flow Areas Workshop	Students will create an HEC-RAS model to utilize the breach functionality and evaluate parameters.	3.5 Workshop - Dam Breach Analysis.pdf 3.5 W - 2D Dam Breach.zip
1345-1415		Review
1415-1430		Break
		Kahoot!
1430-1500	L3.6	SA/2D Connections	Discussion of how to use SA/2D Connections in a 2D Flow Area	3.6 SA2D Connections.pdf
1500-1530	D3.7	Terrain Modifications Demonstration	Introduction to cloning a terrain and adding a simple terrain modification.	3.7 Terrain Modifications.pdf
1530-1700	W3.8	SA/2D Connections	In this workshop, students will utilize 2D Connections (internal hydraulic structures) inside of a 2D Flow Area to improve the river hydraulics model by overriding terrain elevations.	3.8 Workshop - SA2D Connections.pdf 3.8 W - 2D Connections.zip

Thursday

Time		Topic	Objective	Material
0800-0830		Review
0830-0930	L4.1	Troubleshooting Strategies	Discussion on common model stability issues, trouble shooting strategies, and more.	4.1 Troubleshooting.pdf
0930-0945		Break
0945-1030	L4.2	Bridge Modeling	Discussion on modeling a bridge using a 2D Connection using the 1D bridge modeling method as well as developing a detailed mesh to represent the flow constriction.	4.2 Bridge Modeling.pdf
1030-1200	W4.3	Bridge Modeling Workshop	Students will utilize the 1D bridge modeling approach to modeling as well as develop a detailed bridge model to evaluate water surface elevations and velocities in detail.	4.3 Workshop - Bridge Modeling.pdf 4.3 W - Bridge Modeling.zip
1200-1300		Lunch
1300-1330		Review
1330-1345		Break
		Kahoot!
1345-1430	L4.4	Precipitation and Wind	This presentation will discuss the use of the Precipitation and Wind boundary condition in HEC-RAS.	4.4 Precipitation Infiltration and Wind.pdf
1430-1545	W4.5	Precipitation and Wind Workshop	Students will utilize precipitation to create a rain on grid model.	4.5 Workshop - Met Data.pdf 4.5 W - Meteorological Data.zip
1545-1615		Review
1615-1700	L4.6	1D/2D Direct Connections	Learn about hooking a 1D reach directly into a 2D Flow area, as well as having a 1D reach come out of a 2D Flow Area. The concept of 1D to 2D iterations will be introduced.	4.6 1D2D Direct Connections.pdf

Friday

Time		Topic	Objective	Material
0800-0900	D5.1	RAS Mapper Demonstration	This demonstration highlights the various cool functionality in RAS Mapper including terrain modification, terrain resampling, data export, and data import.
0900-0930	L5.2	Introduction to the 3D Viewer	An introduction to RAS Mapper is provided, specifically for visualizing HEC-RAS results.	5.2 HEC-RAS 3D Viewer.pdf
0930-1000	D5.3	3D Viewer Demonstration	The 3D Viewer will be demonstrated interactively
1000-1130		Course Closing	Post-test, course evaluations, oral critique, and closing remarks